Antineoplastic drugs, i.e. drugs used to prevent growth and spread of tumors and malignant cells, present special safety problems to medical personnel, e.g. hospital and pharmacy personnel. This is because most of the drugs are toxic and because they are potentially carcinogenic to healthy humans and may also cause other adverse reactions, e.g. skin irritation or burns. Thus, exposure to the drugs by pharmacists, nurses, physicians and other personnel involved in handling these drugs must be minimized.
There would normally be opportunity for medical personnel to be exposed to these drugs because of their nature. These drugs are not sold as compositions ready for administration. This is because when they are combined with diluent, the compositions which are formed normally have a shelf life ranging from several hours to a few days. Thus, in the ordinary course, diluent (usually sterile water, saline solution, dextrose solution or dextrose-saline solution) is added just prior to administration. Most of the drugs are sold in solid form although some are available in solid or liquid form. The diluent is added to the solid drugs to dissolve them and provide selected concentration. The diluent is admixed with drug in liquid form to dilute it to selected concentration. This admixing of diluent with antineoplastic drug is referred to herein as reconstitution. The term "reconstitution" has come into use in this milieu because the drug to which diluent is added has often been lyophilized.
Reconstitution is normally carried out as follows: The drug container (i.e. bottle or vial) is obtained about one-third to one-half filled with drug, e.g. lyophilized material. A hypodermic needle associated with a diluent containing hypodermic syringe is pushed through the drug container closure to enter the interior of the container, and the syringe is used to inject diluent into the container. The syringe is then removed. The material in the container is then swirled to provide uniformity. A hypodermic syringe is then reinserted into the container, and the diluted drug is pulled into the syringe, and the needle is withdrawn. The injecting of the diluent causes a pressure buildup in the container. As a result of the pressure buildup, drug may escape from the container, e.g. being forced out by the pressure during the injection of diluent or when the needle is withdrawn, and become aerosoled into the environment. As a result, reconstitution is normally carried out utilizing elaborate protective equipment, e.g. hoods and special gowns, face masks and gloves. Special venting devices are also sometimes used to reduce internal pressure. The hazards of antineoplastic drugs and the elaborate precautions for their reconstitution are described in NIH Publication No. 83-2621 which is titled "Recommendations for the Safe Handling of Antineoplastic Drugs".
The hoods recommended for protection in the NIH publication are Class II laminar flow biological safety cabinets which are relatively expensive. In the some 8,000 treatment centers without this equipment, there is a high risk not only to the personnel directly involved but there is danger of escaping drug being aerosoled into the air circulation system of the entire facility.
Consideration has been given to preventing aerosoling of antineoplastic drug during reconstitution and dispensing by attaching a guard to the drug vial. The embodiment which has been commercially available is made of relatively rigid plastic and is over two inches deep and contains an inwardly extending guide passageway for the hypodermic needle, a relatively deep aerosol trapping chamber and structure for locking the device on a drug container consisting of a plurality of inwardly and upwardly projecting tabs. The structure is complicated and of multipiece construction requiring assembly and its depth dimension increases the risk of overturning the container.